I mean, Empire Strikes Back is absolutely one of the greatest movies of the 80s, but I don't really consider it to be an 80s movie. Any more than I consider original Star Wars to be a 70s movie. Just happens to be when it came out.
When Harry Met Sally, on the other hand, might be one of the most quintessential 80s movies there is. The clothes, the hairstyles, the settings, the Sharper Image, the WAVE at a football game...